I am grown old and my memory is not as active as it used to be. When I was younger I could remember anything, whether it had happened or not; but my faculties are decaying now and soon I shall be so I cannot remember any but the things that never happened. It is sad to go to pieces like this, but we all have to do it. [Mark Twain, "Autobiography"]

The ability to remember past experiences or learned information, involving advanced mental processes such as learning, retention, recall, and recognition and resulting from chemical changes between neurons in several different areas of the brain, including the hippocampus. Immediate memory lasts for just a few seconds. Short-term memory stores information that has been minimally processed and is available only for a few minutes, as in remembering a phone number just long enough to use it. Short-term memory is transferred into long-term memory, which can last for many years, only when repeated use of the information facilitates neurochemical changes that allow it to be retained. The loss of memory because of disease or injury is called amnesia.

The collection of information gained from past learning or experience that is stored in a person's mind.

A piece of information, such as the mental image of an experience, that is stored in the memory.

A part of a computer in which data is stored for later use.

The capacity of a computer, chips, and storage devices to preserve data and programs for retrieval. Memory is measured in bytes. See more at hard disk, RAM, ROM.

A part of a computer in which data is stored for later use.

The capacity of a computer, chips, and storage devices to preserve data and programs for retrieval. Memory is measured in bytes. See more at hard disk, RAM, ROM.

The capacity of a material, such as plastic or metal, to return to a previous shape or condition.

The capacity of the immune system to produce a specific immune response to an antigen it has previously encountered.